This invention relates to improvements in an electronic musical instrument comprising tone sources capable of generating frequencies of notes corresponding to keys arranged in a keyboard.
In a prior art electronic musical instrument of a type which comprises tone sources capable of generating frequencies of the notes of the keys and selecting a required one from among such frequencies in accordance with depression of a selected key, all of tones source signals the number of which is the same as a total number of the keys in the keyboard (e.g. 61 if there are 61 keys) must be supplied separately and individually to a keyboard circuit. This construction requires the same number of connection lines as the total number of the keys. Accordingly, if an integrated circuit is employed in a portion (e.g. a tone source circuit) other than the keyboard circuit, a large number of connection pins (e.g. 61) are required for connecting such integrated circuit to the keyboard circuit. As the number of pins used increases, the manufacturing cost of the integrated circuit increases with resulting increase in the manufacturing cost of the electronic musical instrument.